Invasive cattails (Typha angustifolia and Typha × glauca) pose a problem for many Laurentian Great Lakes wetlands, especially sedge/grass meadows. In western Lake Superior, early signs of invasion into sedge-dominated peatlands along the Kakagon and Bad Rivers, owned and managed by the Bad River Band of Lake Superior Chippewa, were noticed in the early 1990s. In 1998, we began tracking expansion of Typha patches and assessing causes and ramifications. Perimeters of patches were delineated with GPS, with repeat delineations in 2005 and 2013. At the Kakagon site, permanent transects were established tangential to the 1998 patch perimeters and perpendicular to those transects, extending into the cattails and outward into sedges. Plant communities were sampled along transects in all years. Transects across stands of non-invasive Typha latifolia were sampled for comparisons but showed little change. In 2005, area encompassed by the Kakagon River patches increased by 66% from 1998; increase was 143% by 2013. The Bad River patches increased by 25% in 2005; further analyses were not possible because some patches had coalesced. Across years, mean Importance Value (IV) for invasive Typha increased for all tangential and perpendicular transects, reflecting expansion into adjacent sedge meadow. Among changes in other species, mean IV for dominant sedge Carex lasiocarpa also decreased on both transects. Typha invasion seems to be directional and not cyclical in relation to lake-level changes, which might have future influence. Given the tendency for early Typha expansion, land managers should scout for new patches and begin treatment soon after discovery.